fix: drop patchPnpmEnv so standalone+self-update works on Windows

[zkochan]

Summary

src/utils/patchPnpmEnv prepends dest/node_modules/.bin (and .bin/bin) to PATH before spawning pnpm install and pnpm store prune. On Windows in standalone mode, node_modules/.bin/pnpm.cmd is an npm-created shim that points at the bootstrap pnpm (currently 11.0.4) — npm linked it there when it installed @pnpm/exe from node_modules. The self-updated pnpm written by pnpm self-update lives at $PNPM_HOME/bin, separately added to PATH via addPath() in install-pnpm.

When the user requests a pnpm version different from the bootstrap under standalone: true on Windows, patchPnpmEnv's .bin entry shadows the self-updated $PNPM_HOME/bin, so the action's internal pnpm install runs on the bootstrap. On a 11.0.x bootstrap this breaks any 11.1+ install flag — e.g. --no-runtime:

ERROR  Unknown option: 'runtime'

POSIX standalone got lucky because .bin and $PNPM_HOME resolve to the same directory there. Non-standalone never tripped on this since the .bin/pnpm symlink for a regular pnpm package keeps working across self-updates.

Fix

• Removed patchPnpmEnv and the now-empty src/utils/ module.
• spawnSync in pnpm-install and pnpm-store-prune now inherits process.env, whose PATH is already correctly fronted by $PNPM_HOME/bin and $PNPM_HOME via addPath() in install-pnpm.

Regression test

Added standalone_windows_self_update to .github/workflows/test.yaml:

• runs-on: windows-latest
• standalone: true
• version: 11.1.0 (different from bootstrap 11.0.4)
• run_install with args: ['--no-runtime']

With the previous code, run_install would have routed through the bootstrap and failed with Unknown option: 'runtime'. With the fix, install runs on the self-updated 11.1.0 and the flag is honored.

Context

Originally found while building pnpm/setup (the new combined pnpm + JS runtime action that always runs standalone). The same bug existed in this repo but was latent because the existing standalone test job only runs on ubuntu, where .bin and $PNPM_HOME collapse to the same directory.

Test plan

• All existing matrix jobs in Test Action pass
• The new Standalone Windows self-update (PATH regression) job passes
• pr-check / check-dist passes (committed dist/index.js matches source)

Summary by CodeRabbit

• Bug Fixes

  • Fixed PATH shadowing regression in standalone mode on Windows that could cause incorrect pnpm version to be used.

• Tests

  • Added Windows-specific test to verify standalone mode properly handles pnpm self-updates without PATH shadowing issues.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 21d16555-fa59-432a-a8ac-c4a3c0ba95d1

📥 Commits

Reviewing files that changed from the base of the PR and between 551b42e and 3ecdba8.

⛔ Files ignored due to path filters (1)

• dist/index.js is excluded by !**/dist/**

📒 Files selected for processing (4)

• .github/workflows/test.yaml
• src/pnpm-install/index.ts
• src/pnpm-store-prune/index.ts
• src/utils/index.ts

💤 Files with no reviewable changes (1)

• src/utils/index.ts

📜 Recent review details

🧰 Additional context used

🧠 Learnings (1)

📚 Learning: 2026-05-11T12:04:07.383Z

Learnt from: zkochan
Repo: pnpm/action-setup PR: 256
File: src/install-pnpm/run.ts:150-166
Timestamp: 2026-05-11T12:04:07.383Z
Learning: In pnpm/action-setup, when validating or forwarding the version value used for `pnpm self-update` and/or `devEngines.packageManager.version`, do not restrict it to exact versions or tags only—pnpm supports semver ranges for these inputs. Ensure any code that parses/validates `devEngines.packageManager.version` (and the value passed to `pnpm self-update`) allows range syntax such as `^`, `~`, and comparators (e.g. `>=8 <10`) instead of rejecting anything that isn’t a single exact version. Note: the plain `packageManager` field is different, so apply this “allow semver ranges” rule specifically to `devEngines.packageManager.version` / `self-update` handling.

Applied to files:

• src/pnpm-store-prune/index.ts
• src/pnpm-install/index.ts

🔇 Additional comments (3)

src/pnpm-store-prune/index.ts (1)

12-17: Env inheritance change for prune path handling looks correct.

This keeps the PATH ordering from earlier setup steps and cleanly removes the Windows standalone shadowing risk without changing prune error handling.

src/pnpm-install/index.ts (1)

14-24: Install spawn behavior update is solid and well-documented.

Relying on inherited process.env here is the right fix for the standalone Windows shim-shadow scenario.

.github/workflows/test.yaml (1)

197-244: Great targeted regression coverage for Windows standalone self-update.

This job exercises the exact failure mode and adds a clear post-check on the resolved pnpm version.

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📝 Walkthrough

Walkthrough

The PR removes custom environment patching utilities and updates pnpm spawn calls across the action to rely on inherited process environment instead, addressing a PATH-shadow regression in Windows standalone scenarios. A new regression test validates the fix.

Changes

Environment Patching Refactor

Layer / File(s)	Summary
Utility Removal src/utils/index.ts	getBinDest function and patchPnpmEnv helper are removed, along with their supporting imports.
Install Environment Handling src/pnpm-install/index.ts	runPnpmInstall no longer passes custom env to spawnSync; inline comments explain why environment override is intentionally omitted to avoid PATH precedence changes that could break Windows self-updated pnpm.
Store Prune Environment Handling src/pnpm-store-prune/index.ts	pruneStore removes patchPnpmEnv import and no longer overrides environment in spawnSync; relies on inherited process environment instead.
Windows Self-Update Regression Test .github/workflows/test.yaml	New Windows-only job standalone_windows_self_update tests the self-update scenario with standalone: true and validates that pnpm --version resolves to the pinned 11.1.0 on PATH.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

Possibly related PRs

• pnpm/action-setup#249: Both PRs refactor how the action handles PNPM's bin destination and environment setup, removing or rewiring getBinDest and patchPnpmEnv.

Poem

🐰 No more patching paths, let them flow free,
The process env leads where pnpm should be.
On Windows it gleams with the self-update cure,
A test guards the regress—the fix is secure! 🎉

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately and concisely captures the main fix: removing patchPnpmEnv to resolve a Windows standalone mode regression where PATH shadowing prevented self-updated pnpm from being used.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-standalone-windows-path

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